No evidence that he's a shit manager, yet (unlike someone like Pardew). If anything, over the last few years, his stock has been steadily rising.
Last season Villa did well to stay up despite looking more likely to go down (new unproven manager and players). But if you want to view it as simply 'nearly went down'....
BTW, every manager needs 'decent' players, ffs. No manager can progress with shit players.